Various types of exercise equipment providing various types of exercise movements are known in the prior art. A weight stack is commonly used for opposing a given exercise motion through a cable and pulley system.
U.S. Pat. No. 7,413,532, which is incorporated herein by reference in entirety, discloses exercise apparatus having a weight stack for opposing a given exercise motion. The weight stack has a first set of a plurality of primary weights vertically stacked on each other, a primary weight selector having a plurality of settings selectively controlling the number of weights to be lifted during the exercise motion, a second set of a plurality of secondary weights, and a secondary weight selector having a plurality of settings selectively controlling the number of secondary weights to be lifted during the exercise motion, the secondary weights providing supplemental incremental weight.
U.S. Pat. No. 7,377,887, which is incorporated herein by reference in entirety, discloses exercise apparatus for guided exercise movement includes a primary arm pivotally mounted to a frame for pivotal movement about a fixed pivot relative to the frame, a movement arm pivotally mounted to the primary arm for pivotal movement relative to the primary arm about a floating pivot relative to the frame, a stationary cam fixed on the frame, and a follower on the movement arm engaging the stationary cam and guided thereby to control the path of movement of the movement arm about the floating pivot during movement of the primary arm about the fixed pivot. The cam has a cam track surface controlling compound movement of the movement arm.